Field of the Invention
The present invention is based on a hand-held power tool.
Description of the Prior Art
DE 10 2005 058 937 A1 has disclosed a drive unit with a hydrostatic transmission and a manual transmission connected thereto. Such transmission arrangements are used, for example, for drive units in construction, farming, and forestry machines or the like. The manual transmission downstream of the hydrostatic transmission has at least two gear stages, during the shifting of which, a synchronizing device adapts the rotation speed of the hydraulic motor of the hydrostatic transmission to the respective driving situation and therefore to the rotation speed of the transmission input shaft of the downstream manual transmission. In order to facilitate this rotation speed adaptation, to avoid shifting jolts, and to improve overall driving comfort while reducing the load and therefore wear on the transmission arrangement, the above-cited patent application proposes adjusting the hydrostatic motor during the shifting procedure so that the rotation speed of the hydraulic motor is slightly greater than the rotation speed that precisely matches a driving situation. Once the rotation speed of the hydraulic motor has been correspondingly increased, then the downstream manual transmission is shifted into the intended gear.
In the above-described transmission arrangement and method for engaging a gear stage in the downstream manual transmission, it is problematic that in certain situations, it is not possible to assure reliable engagement of the intended gear. In particular, for example due to temperature fluctuations and production tolerances, it is not possible to successfully shift into the intended gear predetermined by the vehicle operator. However, in this transmission arrangement and method for shifting gears, no measures are provided for detecting the correct engagement of a gear stage. It is therefore finally left up to the operator to monitor the correct engagement of a gear stage and if need be, to repeat the gear shifting procedure.